1. Field
Exemplary embodiments of the present invention relate to a Complementary Metal Oxide Semiconductor (CMOS) image sensor (CIS), and more particularly, to an apparatus for generating a high dynamic range image and a method thereof.
2. Description of the Related Art
Dynamic range is one of the important criteria for judging the quality of an image sensor. Dynamic range is the maximum range in which an input signal may be processed without distortion. With wide dynamic range, it is possible to acquire a quality image even with great variance in brightness. Conventional color image sensors are known to have narrow dynamic ranges. And, when one or more of the red, green, and blue colors are in a saturated state, the image sensor is unable to accurately capture the image.
In order to overcome the disadvantage of having a narrow dynamic range, synthesis of images having different exposure tunes has been attempted.
Since conventional high dynamic range (HDR) algorithms simply use a weighted sum scheme, noise may occur when synthesizing images.
Furthermore, since the conventional high dynamic range algorithms use local tone mapping to preserve local tone, which is highly complex, it is difficult to implement with hardware.
In addition, the conventional high dynamic range algorithm uses a lot of memory to incorporate luminance at the time of tone mapping.
As a consequence, since conventional high dynamic range (HDR) algorithms are highly complex, noise occurs at the time of synthesis and a lot of memory and other resources are consumed.